Now to an ABC news investigation tonight. The FBI is on the trail of an alleged art scam conspiracy, using an artist so skilled at making fakes they're accused of making millions off of fake master pieces. See if you can tell the difference tonight. Side by side there a mockup of the real thing, one of them a fake. I got it wrong. The trouble is for so many buyers who have been duped, this is hardly a laughing matter, losing millions. Tonight Brian Ross and his team tracking down one of those alleged scammers with a paintbrush. Listen to how he explains himself tonight. Reporter: With wealthy collectors willing to pay tens of millions of dollars for paintings like this. Reporter: So, it's no surprise that the art world is attracting a flock of crooks offering masterful fakes. For example, one of these is an authentic mark rohtko, the other a worthless fake. Many people leaving a big art auction couldn't tell which was which. I think that this is the real one. You think this is the real one? Yeah, is it? Let's see. Oh, that's the fake. You got me. Reporter: The fake rothko, which once sold for $8.3 million, is one of dozens of look-alike works that authorities say were created by one of the great fakers of all time who left New York last year as the FBI began to close in. But now ABC news has found him, in China, in a tiny studio apartment in Shanghai. His name is rei Shen Qian. He was working in times square drawing portraits of tourists when he says he was recruited by two New York art dealers to create fake masterpieces that would sell for a total of some $80 million. My intent wasn't for my fake paintings to be sold as the real thing. But authorities say Qian actually forged the signatures of some of the artists he copied. He told us I was shocked that people mixed them up. But the scam went on for years until this London billionaire, Pierre legrange, realized he had been conned when he paid $17 million for this supposed painting by Jackson Pollock. Experts discovered the yellow paint in the painting was not sold until 14 years after Pollock's death. It turns out it was the work of the accused times square faker. The two art dealers who allegedly recruited the artist also have been charged in the scam. One has pleaded guilty, the other is under arrest in sprain. Many of the fakes were sold through one of New York's most prominent art galleries, which has gone out of business because of the scandal. Brian, thank you. And this just in tonight, word that former secretary of state Henry Kissinger underwent

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